Communications networks are now delivering a wide range of services to customers and are transporting increasing volumes of both voice and data traffic. Each of these different services has attendant bandwidth and quality of service (QoS) requirements, the latter ranging from the “best efforts” requirement of some data services to the high quality guarantee accorded to voice services. Customers may also, in some instances, pay a premium for a guaranteed quality of service to ensure timely delivery of critical traffic.
Basic economic forces are driving the network operators to require a unified carrier network capable of transporting all foreseen classes of traffic across a commonly managed and controlled physical infrastructure. Similarly for basic cost of ownership reasons network operators wish to use whatever transport technology is the least expensive, yet capable of meeting all the service demands.
An increasing problem with such networks is that of management in order to allocate network resources, particularly bandwidth, in a manner which ensures efficient resource utilisation and maximises the revenue return to the network operator(s).
Traditionally, management is a centralised function involving human decision making. With the increasing complexity of communications networks and the increasing variety of services that is being introduced, the use of human intervention to provide the network management function is becoming increasingly difficult, particularly with regard to the issue of revenue maximisation.
A further problem that has been experienced with multi-layer networks is that of congestion management Congestion in any of the network layers can severely restrict the traffic handling capacity and thus limit the potential revenue return for the network operator.